'use client';

// Vrstva pripomienok nad newsletterom (stránka s odkazom aj editor).
// Kontajner musí mať position: relative a moduly v ňom atribút data-module-id.
import React, { useLayoutEffect, useState } from 'react';
import { ReviewComment } from '@/lib/reviews';

interface ModuleLayout {
  width: number;
  tops: Record<string, number>;
}

// Prepočet súradníc kliknutia na súradnice ukotvené k modulu
export function pointToModuleCoords(
  container: HTMLElement,
  clientX: number,
  clientY: number,
  moduleId?: string
): { moduleId: string; x: number; y: number } | null {
  const rect = container.getBoundingClientRect();
  const modules = Array.from(container.querySelectorAll<HTMLElement>('[data-module-id]'));
  const target = moduleId
    ? modules.find((m) => m.dataset.moduleId === moduleId)
    : modules.find((m) => {
        const r = m.getBoundingClientRect();
        return clientY >= r.top && clientY <= r.bottom;
      }) || modules[modules.length - 1];
  if (!target || !rect.width) return null;
  const top = target.getBoundingClientRect().top;
  return {
    moduleId: target.dataset.moduleId!,
    x: Math.min(1, Math.max(0, (clientX - rect.left) / rect.width)),
    y: Math.round(clientY - top)
  };
}

// Poloha modulov v kontajneri; prepočíta sa pri zmene veľkosti a obsahu
export function useModuleLayout(containerRef: React.RefObject<HTMLElement | null>, deps: unknown[]): ModuleLayout | null {
  const [layout, setLayout] = useState<ModuleLayout | null>(null);
  useLayoutEffect(() => {
    const el = containerRef.current;
    if (!el) return;
    const measure = () => {
      const cr = el.getBoundingClientRect();
      const tops: Record<string, number> = {};
      el.querySelectorAll<HTMLElement>('[data-module-id]').forEach((m) => {
        tops[m.dataset.moduleId!] = m.getBoundingClientRect().top - cr.top;
      });
      setLayout({ width: cr.width, tops });
    };
    measure();
    const ro = new ResizeObserver(measure);
    ro.observe(el);
    // obrázky sa načítavajú postupne a menia výšku modulov
    el.addEventListener('load', measure, true);
    return () => {
      ro.disconnect();
      el.removeEventListener('load', measure, true);
    };
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [containerRef, ...deps]);
  return layout;
}

interface AnnotationLayerProps {
  layout: ModuleLayout | null;
  comments: ReviewComment[];
  showDone?: boolean;
  selectedId?: string | null;
  onSelect?: (id: string | null) => void;
  // Akcie v bubline vybranej pripomienky (napr. Hotovo v editore)
  renderActions?: (c: ReviewComment) => React.ReactNode;
}

export const AnnotationLayer: React.FC<AnnotationLayerProps> = ({
  layout,
  comments,
  showDone = true,
  selectedId,
  onSelect,
  renderActions
}) => {
  if (!layout) return null;
  const visible = comments.filter((c) => (showDone || !c.done) && layout.tops[c.module_id] !== undefined);
  const pos = (moduleId: string, x: number, y: number) => ({ left: x * layout.width, top: layout.tops[moduleId] + y });
  const commentNumbers = new Map(comments.filter((c) => c.kind === 'comment').map((c, i) => [c.id, i + 1]));

  return (
    <div className="absolute inset-0 pointer-events-none z-30">
      {/* Kresby */}
      <svg className="absolute inset-0 w-full h-full overflow-visible">
        {visible
          .filter((c) => c.kind === 'drawing' && c.path && c.path.length > 1)
          .map((c) => (
            <polyline
              key={c.id}
              points={c.path!.map(([x, y]) => {
                const p = pos(c.module_id, x, y);
                return `${p.left},${p.top}`;
              }).join(' ')}
              fill="none"
              stroke={c.color}
              strokeWidth={selectedId === c.id ? 5 : 3}
              strokeLinecap="round"
              strokeLinejoin="round"
              opacity={c.done ? 0.3 : 0.9}
              className="pointer-events-auto cursor-pointer"
              onClick={(e) => {
                e.stopPropagation();
                onSelect?.(selectedId === c.id ? null : c.id);
              }}
            />
          ))}
      </svg>

      {/* Komentáre (špendlíky) a texty */}
      {visible
        .filter((c) => c.kind !== 'drawing')
        .map((c) => {
          const p = pos(c.module_id, c.x, c.y);
          const isSelected = selectedId === c.id;
          return (
            <div
              key={c.id}
              className="absolute pointer-events-auto"
              style={{ left: p.left, top: p.top, zIndex: isSelected ? 40 : 30 }}
              onClick={(e) => {
                e.stopPropagation();
                onSelect?.(isSelected ? null : c.id);
              }}
            >
              {c.kind === 'comment' ? (
                <div
                  className={`-translate-x-1/2 -translate-y-full w-7 h-7 rounded-full rounded-bl-none rotate-[-45deg] flex items-center justify-center shadow-lg border-2 border-white cursor-pointer ${c.done ? 'opacity-40' : ''} ${isSelected ? 'scale-125' : ''}`}
                  style={{ backgroundColor: c.color }}
                >
                  <span className="rotate-45 text-[11px] font-black text-white">{c.done ? '✓' : commentNumbers.get(c.id)}</span>
                </div>
              ) : (
                <div
                  className={`-translate-y-1/2 max-w-[260px] px-1.5 py-0.5 rounded bg-white/85 text-[13px] font-bold leading-tight whitespace-pre-wrap shadow cursor-pointer ${c.done ? 'opacity-40 line-through' : ''} ${isSelected ? 'ring-2 ring-offset-1' : ''}`}
                  style={{ color: c.color }}
                >
                  {c.text}
                </div>
              )}
            </div>
          );
        })}

      {/* Bublina vybranej pripomienky */}
      {(() => {
        const c = visible.find((v) => v.id === selectedId);
        if (!c || c.kind === 'text') {
          return c && renderActions ? (
            <div className="absolute pointer-events-auto" style={{ left: pos(c.module_id, c.x, c.y).left, top: pos(c.module_id, c.x, c.y).top + 14 }}>
              <div className="flex gap-1 bg-white rounded-lg shadow-xl border border-gray-200 p-1">{renderActions(c)}</div>
            </div>
          ) : null;
        }
        const anchor = c.kind === 'drawing' && c.path?.length ? c.path[c.path.length - 1] : [c.x, c.y];
        const p = pos(c.module_id, anchor[0], anchor[1]);
        return (
          <div
            className="absolute pointer-events-auto w-64 bg-white rounded-xl shadow-2xl border border-gray-200 p-3 text-left"
            style={{ left: Math.min(p.left + 12, layout.width - 256), top: p.top + 8, zIndex: 50 }}
            onClick={(e) => e.stopPropagation()}
          >
            <div className="flex items-center justify-between gap-2 mb-1">
              <span className="text-[11px] font-bold text-gray-900 truncate">{c.author || 'Anonym'}</span>
              <span className="text-[10px] text-gray-400 shrink-0">{new Date(c.created_at).toLocaleString('sk-SK')}</span>
            </div>
            {c.text ? (
              <p className="text-xs text-gray-700 whitespace-pre-wrap">{c.text}</p>
            ) : (
              <p className="text-xs text-gray-400 italic">{c.kind === 'drawing' ? 'Kresba bez poznámky' : ''}</p>
            )}
            {c.done && <p className="mt-1 text-[10px] font-bold text-emerald-600">✓ Hotovo</p>}
            {renderActions && <div className="mt-2 flex gap-1.5">{renderActions(c)}</div>}
          </div>
        );
      })()}
    </div>
  );
};